zOwie Omega Discussion Forum

: The uni-directional bezel is not used to time
: the amount of air you have left in your tank
: as this is fairly independent from the time
: you are spending under water: the critical
: factor is the depth for your air
: consumption. Let's say a 12 liters tank give
: you one hour of air at the surface it will
: only give you c. 10 minutes of air at 60
: meters.

: So the uni-directional bezel is indeed used to
: measure TIME but for another purpose than
: air autonomy it is used to calculate (or
: avoid) your decompression stops.

: For example if you spend 30 minutes at 30
: meters you will have 9 minutes of deco stops
: but if you spend 31 minutes at 30 minutes
: you might need 12 minutes deco stops. That
: is why it so important for the bezel to be
: uni-directional: if you turn it
: inadvertantly during the dive it will show
: you a LONGER diving time and then you will
: do LONGER deco stops that what you really
: need which means extra security.

: If you were to have a bi-directioanl bezel and
: you were recording a shorter diving time by
: mistake, thus doing shorter decompression
: stops that needed this could results in a
: very serious accident that could leave you
: permanently paralsied or dead.

: I hope I have not bored you too much with
: technical details... If I have sorry...

: Kind regards,

I never really thought about that. That's pretty interesting. I had always thought it was for timing your tanks capacity, never really thought about decompression (certainly a very critical purpose than.)